基于MVC模型的SVG生产实时监控系统设计与实现

针对传统生产实时监控系统灵活性差的问题,应用SVG技术进行了改进,适用于异构系统环境;并结合MVC架构设计并实现了扩展性高、移植性好、灵活性强的J2EE实时监控系统。     

Long-term Energy Demand and CO_2 Problem in the PRC

The long-term energy demand in China and the-Chinese share in global CO2 emission are forecasted on the basis of scenarios of population growth and economy development up to 2050 proposed in view of the interaction of energy, economy, environment and social development. The total energy demand in 2050 will reach 4.4~ 5.4 billion tce. It is shown in energy supply analysis that coal is China's major energy in primary energy supply. The share of CO2 emission in the future Chinese energy system will be out of proportion to its energy consumption share because of the high persentage of coal to be consumed. It will reach about 27%. The nuclear option which would replace 30.7% of coal in the total primary energy supply will reduce the share by 9.8%. So the policy considerations on the future Chinese energy system is of great importance to the global CO2 issues.     

Mobile Robot Control Based on Dynamic Potential

An efficient method is presented for implementing mobile robot perception-action behaviors, based on time-varying environment potential field approach. First, in this paper, the concept of dynamic potential U(x,y,z,t) is proposed for representing the environment of a mobile robot, and the form of U(x,y,z,t) is deduced, and then the velocity control of the vehicle with two wheel is directly calculated by transition function T of U(x,y,z,t). Finally, the perception-action layer is successfully implemented for avoiding collision, wandering, and integrating path planning and steering control on THMR-Ⅱ (TsingHua university Mobile Robot system). Based on sonar array signals, the experimental results are given to show that THMR-Ⅱ has better reflexive function, real-time obstacle avoidance, adaptablity and robustness for complex environments.     

在相对论性激光-等离子体系统中模拟激光参数对等离子弧柱形态的影响

基于相对论性激光-等离子体动力学理论和PIC方法建立了激光入射等离子弧柱的模型,该模型描述了激光入射等离子弧后粒子的运动,并模拟了弧柱形态的变化。通过改变激光的平均功率、脉冲宽度以及重复频率,模拟等离子弧柱形态变化,得到的激光参数对等离子弧柱形态的影响规律。通过控制弧柱的直径可以提高材料的熔积性能。计算结果表明增大激光平均功率、脉冲宽度,可以更深地压缩等离子弧;但是,重复频率的影响则会出现波动现象。激光等离子复合加工更适合于精细加工。     

A New Signal Processing Technique of π/4-DQPSK Modem Based on Software Radio

1 .INTRODUCTIONπ/4 DQPSKmodemhasbeenchosenasthemodemschemeinmanymobilecommunicationsystems[1 ] .Inπ/4 DQPSKmodem ,theinformationbitsaremappedintophasetransitionsratherthanabsolutephasevalues.Thisencodingofinformationinthetransitionsovercomesthephaseambiguityproblemsresultingfromtheestimationofcarrierphaseinnon differentialPSKsystems.Soπ/4 DQPSKallowsforsimplebasebanddifferentialdemodulation .Further,inπ/4 DQPSK ,themaximumphaseshiftisrestrict edto± 1 35°(ascomparedto± 1 80…     

A New Method with High Confidence for Validation of Computer Simulation Models of Flight Systems

Computer simulation models may by used to gain further information about missile performance variability. Model validation is an important aspect of the test program for a missile system. Validation provides a basis for confidence in the model's results and is a necessary step if the model is to be used to draw inference about the behavior of the real missile. This paper is a review of methods useful for validation of computer simulation models of missile systems and provides a new method with high degree of confidence for validation of computer simulation models of missile systems. Some examples of the use of the new method in validating computer simulation models are given.     

Persistence of soil organic matter as an ecosystem property

Globally, soil organic matter (SOM) contains more than three times as much carbon as either the atmosphere or terrestrial vegetation. Yet it remains largely unknown why some SOM persists for millennia whereas other SOM decomposes readily--and this limits our ability to predict how soils will respond to climate change. Recent analytical and experimental advances have demonstrated that molecular structure alone does not control SOM stability: in fact, environmental and biological controls predominate. Here we propose ways to include this understanding in a new generation of experiments and soil carbon models, thereby improving predictions of the SOM response to global warming.     

A dipole mode in the tropical Indian Ocean

For the tropical Pacific and Atlantic oceans, internal modes of variability that lead to climatic oscillations have been recognized, but in the Indian Ocean region a similar ocean-atmosphere interaction causing interannual climate variability has not yet been found. Here we report an analysis of observational data over the past 40 years, showing a dipole mode in the Indian Ocean: a pattern of internal variability with anomalously low sea surface temperatures off Sumatra and high sea surface temperatures in the western Indian Ocean, with accompanying wind and precipitation anomalies. The spatio-temporal links between sea surface temperatures and winds reveal a strong coupling through the precipitation field and ocean dynamics. This air-sea interaction process is unique and inherent in the Indian Ocean, and is shown to be independent of the El Ni?o/Southern Oscillation. The discovery of this dipole mode that accounts for about 12% of the sea surface temperature variability in the Indian Ocean--and, in its active years, also causes severe rainfall in eastern Africa and droughts in Indonesia--brightens the prospects for a long-term forecast of rainfall anomalies in the affected countries.     

Bone marrow cells regenerate infarcted myocardium

Myocardial infarction leads to loss of tissue and impairment of cardiac performance. The remaining myocytes are unable to reconstitute the necrotic tissue, and the post-infarcted heart deteriorates with time. Injury to a target organ is sensed by distant stem cells, which migrate to the site of damage and undergo alternate stem cell differentiation; these events promote structural and functional repair. This high degree of stem cell plasticity prompted us to test whether dead myocardium could be restored by transplanting bone marrow cells in infarcted mice. We sorted lineage-negative (Lin-) bone marrow cells from transgenic mice expressing enhanced green fluorescent protein by fluorescence-activated cell sorting on the basis of c-kit expression. Shortly after coronary ligation, Lin- c-kitPOS cells were injected in the contracting wall bordering the infarct. Here we report that newly formed myocardium occupied 68% of the infarcted portion of the ventricle 9 days after transplanting the bone marrow cells. The developing tissue comprised proliferating myocytes and vascular structures. Our studies indicate that locally delivered bone marrow cells can generate de novo myocardium, ameliorating the outcome of coronary artery disease.